Helical Carbon Segment in Carbon-Boron-Nitride Heteronanotubes: Structure and Nonlinear Optical Properties

• Published in: ChemPlusChem (Weinheim, Germany) Vol. 79; no. 5; pp. 732 - 736
• Main Authors: Zhong, Rong-Lin, Sun, Shi-Ling, Xu, Hong-Liang, Qiu, Yong-Qing, Su, Zhong-Min
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.05.2014; WILEY‐VCH Verlag; Blackwell Publishing Ltd
• Subjects: Boron; Carbon; carbon nanotubes; Chemistry; density functional calculations; electronic structure; heteronanotubes; Nanotubes; nonlinear optics; Optical properties
• ISSN: 2192-6506; 2192-6506
• DOI: 10.1002/cplu.201300381

Carbon–boron–nitride heteronanotubes have attracted much interest owing to their adjustable properties and wide applications in many fields. In this work, the structures and first hyperpolarizabilities (β0) of a series of HA‐n and isoelectronic PA‐n heteronanotubes are investigated, in which HA‐n is composed of a helical C segment and BN segment, and PA‐n is composed of an arc C segment and BN segment. Interestingly, the helix C segment in HA‐9 leads to a fascinating long‐range charge‐transfer character. As a result, the β0 value of HA‐9 is 1.80×104 a.u., which is much larger than that of PA‐9 (4.99×103 a.u.). Significantly, the β0 value of the C segment in HA‐9 is 1.72×104 a.u., whereas that of the BN segment in HA‐9 is much smaller (7.48×102 a.u.). In this context, the larger β0 value of HA‐9 is essentially induced by the helix topological effect of the C segment. It is our expectation that this new knowledge about heteronanotubes might provide more ideas for further exploration of sp2‐hybridized carbon segments with special topologies. Helix topological effect: The helix C segment in HA‐9 leads to fascinating long‐range charge‐transfer character. As a result, the β0 value of HA‐9 is 1.80×104 a.u., which is clearly larger than that of PA‐9 (4.99×103 a.u.). Further investigations show that the larger β0 value of HA‐9 is essentially induced by the helix topological effect of the C‐segment (see figure).